The invention relates to a trampoline which is adapted to be used on all types of surfaces, including both land and water surfaces. In the past, trampolines have been designed for use either on land or water, thereby limiting their use. It is therefore desirable to provide a trampoline which can be used on many different surfaces to increase its versatility.
A pneumatic trampoline designed specifically for use on land or a hard surface is shown in U.S. Pat. No. 3,130,816. In this arrangement, the pneumatic tube is deformed upon impact of a person jumping on the upper wall of the device, and the tube subsequently rebounds to provide lift to the jumper.
U.S. Pat. No. 4,576,375 discloses a trampoline specifically designed for use on water. A pneumatic tube is used to support the trampoline on water, and a base cover is attached to the lower interior of the tube to seal off rapid air flow through the tube opening and create a substantially closed volume between the base cover and the water surface.
The above prior art devices cannot be successfully employed on surfaces other than that for which they are specifically designed, and accordingly, the use thereof is limited. A problem existing with each of the foregoing discussed patented trampolines is that there is no provision for release of air pressure existing on the underside of the trampoline mat which is generated by jumpers using the trampoline. This air pressure will tend to distort the devices and cause them to move laterally. This of course will cause undesirable wear and tear on the bottom of a trampoline supported on land or other hard surface. In the case of a trampoline supported on water, water turbulence and waves will be generated thereby making the trampoline unstable.
A problem with constructions such as shown in U.S. Pat. No. 4,576,375 and our copending U.S. patent application Ser. No. 07/730,482, filed Jul. 16, 1991 is that they employ relatively heavy metallic components. These metallic components make the construction more expensive, and the weight of the metallic components increases the cost of transporting the device from one location to another. The metallic components also present a safety hazard since a jumper may be injured if he accidentally comes into contact with such components. Furthermore, assembly and disassembly of these constructions are difficult and time-consuming.